html, body { margin: 0; height: 100%; overflow: hidden; background: #101015; }
#renderCanvas { width: 100%; height: 100%; display: block; touch-action: none; }
#hud { position: fixed; top: 8px; left: 8px; color: #cde; font: 14px system-ui;
  background: rgba(0,0,0,.5); padding: 6px 10px; border-radius: 6px; z-index: 10; }